Project Summary: This T32 Training Grant proposal is a competitive renewal of a successful program for Interdisciplinary Training in Environmental Health that builds on the experience of our PhD program in Environmental Health Sciences (EHS) over the past 15 years. Our program seeks to successfully integrate skills in biomedical sciences with public health into an interdisciplinary training experience for the next generation of environmental health scientists. We have attracted and trained truly exceptional doctoral students in our PhD program and this T32 training grant has been and continues to be critical to these achievements. The training program is guided by the Program Director (PD; Dr. Andrea Baccarelli), with assistance from a Deputy Director of Research (Dr. Joseph Graziano), a Deputy Director of Education (Dr. Greg Freyer) and a faculty Admission/Steering Committee. With the arrival this year of four new faculty into the EHS Department, including Dr. Andrea Baccarelli as the new EHS Departmental Chair and PD of this competitive renewal, this training program has been redesigned to revolve around three main themes of research that will be well positioned to successfully address current and emerging-day topics and challenges in environmental health: a) Exposure Science and Environmental Epidemiology; b) Environmental Epigenetics and Molecular Mechanisms; and c) Environmental Prevention and Mitigation. The proposal requests support only for pre-doctoral PhD students (N = 5, up from the current 4), each of whom would receive two years of support from this grant during their first two years of study. All students are actually guaranteed five years of support by the institution (tuition, stipend, health insurance, all fees), with the remaining support coming from faculty grants and/or institutional support. All trainees take rigorous coursework in their first two years, tailored to the theme of their research, including coursework regarding the Responsible Conduct of Research. In their first year, trainees conduct three laboratory rotations with different training faculty, before selecting a dissertation mentor. Following the completion of their qualifying exam, the research progress of each student is carefully guided and monitored at least twice/year by a thesis committee comprised of the student's mentor plus four additional training faculty. A total of 19 experienced training faculty are available to serve as mentors to PhD students; the faculty currently hold federal grant awards totaling more than 20 million dollars/year, or roughly $300,000/year per training faculty. The EHS Department has a strong record of training minority students; of the 16 current PhD students in the Department, 5 (31%) are minority trainees. The program has a large (45-60/year) and extremely strong applicant pool, and a high rate of acceptance among those offered positions. Past and current trainees have outstanding peer reviewed publication records during and after their dissertation research, and land competitive positions in academia, government, industry and many diverse public health settings.